that phasing plan involves a environmental assessment to see anything unhealthy in this environment or in that square. we have to check the integrity of the buildings. because of that the city is unable to release a time frame when the square will be reopened to the public, when people will come back to their businesses. jenna? jenna: more when we get it, mike. mike tobin live in boston today. jon: charges in connection with the boston terror attacks and the aftermath could come as early as today as investigators continue to look for answers. they want to know if dzhokhar tsarnaev and his brother acted alone. but his serious injuries are slowing their progress. chief intelligence correspondent catherine herridge is live in washington right now. so what are we learning about the fbi's contact with the suspect, catherine? >> reporter: a leading republican briefed by the assistant director of the fbi last night tells fox news the risch shun equivalent of the fbi sent a letter to the bureau that they suspected older brother was a islamist extremist and believe in their cause. tamerlan tsar